Elastic-fluid turbine.



J. F. METTEN.

ELASTIC FLUID TURBINE.

APPLICATION FILED NOV. 9, 1911. RENEWED NOV. 9, 1912 W/T/VL'SSESPatented Dec. 31, 1912.

I I I l UNITED STATES PATENT OFFICE.

JOHN F. METTEN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE WM. CHAMP& SONS SHIP 8:. ENGINE BUILDING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELASTIC-FLUID TURBINE.

vApplication filed November 9, 1911, Serial No. 659,839. RenewedNovember 9, 1912.

Y '0 all whomit may concern Be it. known that I, JOHN F. ME'rrnN, acitizen of the United States, residing at Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Elastic-I luid Turbines, of WlllCh the followingis a full, clear, and exact specification.

Thisinvention relatesto elastic fluid turbines and has for its objectanimproved mounting for the blades in the revolving or stationary memberof a steam or gas turbine, by means of which they are more securelylocked against displacement under cent-rifugal thrust and torsionalstrainsand may be assembled with greater convenience than by the methodscommonly employed, and by which a lighter and stronger structure may besecured.

Various methods of securing the blades to the elements of a turbine havebeen heretofore employed. In one method, grooves are cut in the drumsthe full width of the blades, which are held in place by soft metalpacking pieces spaced between, and calked so as to be swelled intoserrations cut into the grooves and the adjacent sides of the blades.This method,-although cheap in construction, is objectionable in that,if any calked section is defective, the blades are liable to strip underthe centrifugal strains, which produces disastrous results to themachine. Other methods are to rivet the blade to a strip of metal andbend the latter to fit a groove of the drum; or to provide an undercutgroove and mill the roots of the blades of a proper shape to dovetailwith the undercut channels' In all of these types a shallow groove isemployed so that with Weak or careless calkin'g the blades are liable towork loose and become displaced under the combined effort of rotary andcentrifugal strain or the blades; will lack proper lateral rigidity ifthe lit in the grooves is not perfectly tight. By reason oftheirditlicult mechanical structure, some of them are, moreover, open toobjection on account of manufacturing expense.

, By my construction I overcome possibility of damage through defectivelocal callging and secure the blades in position by a Specification ofLetters Patent.

Patented Dec. 31, 1912.

Serial No. 730,492.

cross section of the support. I secure these" desirable results bymaking the root of the blade deep relatively to its width and lock theblades to their support by milling hemispherical recesses on oppositesides of the root to receive steel balls by which the blades are firmlylocked against relative slip. Wide shoulders are formed near thejunction of the root of the bladewhich find a secure abutting surface onthe face of the drum or disk, and the blades are assembled withintervening soft metal space blocks and then driven into undercut orserrated channels until the shoulders squarely engage the face of thedrum, the space blocks thereby extending into the serrations and inconjunction with the steel balls, anchoring the root in two planesagainst displacement under centrifugal thrust or circumferential strainor flexure. i 1

My invention, therefore, consists in a turbine blade mounted in a deepand relatively narrow recessed groove in the rotary element and lockedin place by unyielding walls at all faces of its root.

I t embodies also various other more specific features, thenoveltyofWhich will be hereinafter more fully describedin the speci'fication and definitely indicated in the claims.

in the accompanying drawings which illustrate my invention, Figure 1 isa part sectional view of a blade mounting embody iug my invention; Fig.2 is a similar View on a plane at right angles to that of Fig. 1; Fig. 3is a top plan view of Fig. 1; Fig. 4 is a sectional view showin myinvention as applied to a disk rotor o a turbine.

Referring now to the drawings in detail, 1 represents the turbine blade,the root of which, 2, is milled off with square shoulders 3 to engagecorresponding'wall's on the face of the drum or disk of the rotaryelement of the turbine. Suitable slots are milled in the face of the.drum or disk in which the ratio of the width to the depth is very muchless than in the systems of mounting heretofore in vogue. or serrated asindicatedat t, to it .int.e

being; died with a smell hemispherical recess :2 adopted to form a seatfor a rein-tirely hard ball, such as steel, or other si' itable keytoloclt the blades and the filling meets in position;

Between each pair er blades is placed a filling block t of metal, thelateral faces of which are recessed to form. nseat for the balls. Agroup of the blades are assembled in the slot side by, side with theintcrveiling packing blocks, steel bells fitting: snugly between thecorresponding cavities block and. root of the blade, and the blocks aresubjected to pressure by milking the exposed ends so as to cause thesoft metal to expand into the serrations or groo es in the walls of thedrum. The bells thus form a rigid connection between the block 6 and theroot. of the blude,'encl if any peeking block should. not be czi-lkedhard enough to thoroughly iillthe'serrations in th groove, the ballswill form an interlock between it and the adjacent'blades, which willpreventthecentrifugal force due to the revolution of the cylinder ordisk carrying the blades from pulling out the blade without also drawingout the packing block. An important. advantage of: this form ofconstruction is the great. rigidity due to the milled shoulders 2, 3 andthe depth of the slot; moreover, as the s.ots are cut in raisedshoulders on the surface oi the drum, as indicatcd in Fig. l, thethickness of metallic Wall between these shoulders can be less than thethickness required. if the slots were the full width of" the blade,which means-a vli ghtcr form tion, the space he dcrs being adapted forthe shrouding on nudes, scly to ether, to fill the groove, and theexposed ends of the blocks culkcd so as to expand into the serrations inside of groove. It ll be evident that, by reason of the =tiun oi themilking material into the Tutituis of the grooves and by reason ofcompletely embeddiu the interlocking the blades are rigidly supportedcentrifugal thrust on all sides of the root. Elorerrser, by reason ofthe depth of the root, a nnich more stable construction is providedagainst circumferential thrust asihe distance is greater between the toron the shoulder-*5 2, 3, and the If the blades are lines show thesection of metal required in revolving disks with undercut slots toreceive the blade, and the full lines show the section of metal requiredfor the type of binding herein described, It will be noted that tlupartrepresented the reference characters 6, 7, 8, 9 replaces the packingsections or dislzn'ico pieces between the blades of this type of turbineand that this is not addiiionel weight, might at first appear.

Higving thus described my invention, I ileclai'e that what I claim asnew and desire to secure by Letters Patent, is:

1. In a turbine, the combination of a blade having a root embedded inserrated groove in a, supporting member, hard metal keys interlocl-zingwith sockets in the root, and soft metal packing filling the groove andembedding the keys and serrations.

2. In a turbine, the combination or a se ries of blades having rootsembedded in a serrated groove in a supporting member, a series of steelballs seated in cavities in the roots, and soft-metal compressiblepecking separating the roots of the hind In a turbine, the cornhi bladehaving a root deep cliiti width with wide bearing shcmldcrs to engagethe periphery of the support, and. rigid k ys. iniei'lnclt ug on allsides with the root 7. 2 wells to prevent displaceci' centrifugal orrotary thrust. -l. ln a turbine, the combiimtion of a series of bladeswith intervening soft metal dercut groove in one of the elements, spaceblocks of soft metalcompressed in serrations of the grooves, and a ofsteel halls interlocking with recessed surfaces of the roots of theblades and with the compressed'spaee blocks.

6. In a till-blue, the combination of a series of grooved bladeshaving'deep roots with hearing shoulders engaging the face of the rotary-element, an undercut g'oove in the rotary element, a series of steelballs interlockingwith the side walls of thejroots, and soft metal spaceblocks partly surrounding each ball and the undercut groove andcompacted into tight engagement therewith.

7. 1m a turbine, thecombination of a series of 'groove-d blades havingroots .relatively deep to their thlckness'and right on gled bearingshoulders engaging the face of the rotary element, an undercut groove inthe face of the rotary element, a sericsof steel-balls engaginghemispherical steel neccsses in the side walls of the roots, and softmotel space blocks with corrcsgwnding hemispherical recesses, the spaceblocks being compacted into the grooves to, .mnbed the 1 In testimonvwhereof I afiix my signature, roots and undercut grooves. 111 Drogonmrof two witncssis.

S. In :1 turbine. the combination of :1 W V. v

' JOHN P. MIJL'ILA.

groovad support, :1 plurality of blades spare 5 blocks and interlockingballs botweon the \\'irm;-s es:

blades, whereby the blades are locked in lsur Ax-nxovr, position. Cum.\V \VILLIAM.

